I felt like I heard two orchestras onstage these past few days: the one that played Tchaikovsky's second and third symphonies, and the one that played Tchaikovsky's fourth and fifth.

The first orchestra played the notes and the passages with all the unremarkable familiarity of a morning commute, like it happened, like it left no lasting impression and that was the end of it. You left, you arrived and that was all.

Then there was that other orchestra, the one that managed to somehow blaze new trails through even the most well-trodden of musical paths, the one that made new discoveries within oft-repeated ideas.

This is how I succinctly characterize the Mariinsky Theatre Orchestra's two appearances in Costa Mesa's Renée and Henry Segerstrom Concert Hall on Oct. 13 and 17.

The famed Russian ensemble from St. Petersburg — brought locally thanks to the Philharmonic Society of Orange County and led by Valery Gergiev — was, at its numerous highs, the listener's ladder to Tchaikovsky-infused heaven. And when not enjoying the air up there, we were Earth-bound and in mere contentment.

That said, I never found myself overly inspired by the Mariinsky's rendition of Symphony No. 2 (aka the "Little Russian"), and while its playing of Symphony No. 3 had its charms, the two could never match the greatness that came from Gergiev and his Mariinsky playing symphonies four and five. Those performances were what showed why the orchestra has the stellar reputation it's earned.

Tchaikovsky's second and third symphonies, by most standards, don't reach the qualities of his fourth and fifth (and especially his sixth). It's why they're less-often performed and little talked about within the classical world.

Though the plus side to the Mariinsky playing what I'll dub some "pre-Tchaikovsky" — Tchaikovsky before he became the popular Tchaikovsky we know and love — was that it served a more intellectual stimulation than an emotional one. We active listeners could appreciate hearing the composer's early development, his eventual coming upon an unmistakably intense romantic style.

Gergiev — lacking a baton both nights, as he is known to use only his hands (or even a toothpick) — used the score to conduct symphonies two and three. He didn't on four and five. He left things to his own memory, his own instincts and his orchestra's remarkable skill.

Those instincts clearly shined. The music ebbed and flowed as it need be, never too rushed when orchestral color should prevail and, much to my liking, showing the considerable sentimentality we Tchaikovsky fans ache for.

Gergiev pranced about his center-stage spot throughout the two evenings. He did not use an elevated podium like most conductors do. Had he, his two-footed gusto might have sent him tumbling off it.

It also wouldn't have allowed him to call upon his front-row musicians so intimately. On several an occasion, his conducting arms reached so close that I thought he was going to snatch the violin out of the concertmaster's hands.

There was the occasional flub in the music-making, likely due to an ambiguous direction by Gergiev or the Mariinsky's action-packed, back-to-back playing schedule (with 23 performances in October alone). Still, they were nothing too distracting from this group's otherwise particularly mighty brass and a string sound to savor.

BRADLEY ZINT is a copy editor for the Daily Pilot and a classically trained musician. Email him story ideas at bradley.zint@latimes.com.